Exploring, drilling and completing hydrocarbon and other wells are generally complicated, time consuming and ultimately very expensive endeavors. As a result, over the years, well architecture has become more sophisticated where appropriate in order to help enhance access to underground hydrocarbon reserves. For example, as opposed to wells of limited depth, it is not uncommon to find hydrocarbon wells exceeding 30,000 feet in depth. Furthermore, today's hydrocarbon wells often include deviated or horizontal sections aimed at targeting particular underground reserves. Indeed, at targeted formation locations, it is quite common for a host of lateral legs and fractures to stem from the main wellbore of the well toward a hydrocarbon reservoir in the formation.
The above described fractures may be formed by a fracturing operation, often referred to as a stimulation operation. The stimulation or fracturing operation, involves pumping of a fracturing fluid at high pressure into the well in order to form the fractures and stimulate production of the hydrocarbons. The fractures may then serve as channels through the formation through which hydrocarbons may reach the wellbore. The indicated fracturing fluid generally includes a solid particulate or aggregate referred to as proppant, often sand. The proppant may act to enhance the formation of fractures during the fracturing operation and may also remain primarily within fractures upon their formation. In fact, the fractures may remain open in part due to their propping open by the proppant.
The above described proppant for the fracturing operation may be supplied from a proppant delivery unit located at the oilfield near the well. This unit is generally very large due to the amount of proppant that may be required for any given fracturing operation. For example, where the proppant is a conventional dry sand, a fully loaded unit may exceed half a million pounds in weight. Once more, as wells become deeper and of ever increasing complex architecture, efforts to provide even larger ready supplies of proppant at the oilfield are increasingly common. That is, more downhole fracturing locations may be involved, thus requiring a greater available supply of proppant.
From an equipment standpoint, greater on-site or near-site supplies of proppant may include the use of mobile silos or even larger stationary silos that are used to gravity feed a blender therebelow. Thus, a proppant slurry may be formed and utilized in short order to support various fracturing operations. As a practical manner, however, this means that potentially several million pounds of proppant may require transport and storage at a given location.
A variety of challenges are presented where management of such massive amounts of proppant or any aggregate is sought. For example, as a silo is filled or emptied for sake of ongoing operations, it is quite difficult to measure with precision the exact amount of proppant being added or consumed. That is, as a given operation calls for the addition or consumption of a particular type of proppant from a silo, it is likely to be in the neighborhood of tens of thousands of pounds. This may involve an operator manually feeding a line to a silo for a period and estimating an amount added (or consumed). That is, at present, there is no practical manner to precisely monitor the increasing or decreasing volume of proppant in a given silo in an automated manner during operations.
Furthermore, if proppant becomes unexpectedly depleted leaving the mixer empty, the entire operation may require shutting down. As a result, operations often proceed with substantially more proppant available than is actually required for the operation. That is, as opposed to shutting down operations at a substantial cost of time and frustration for the well developer, expenses are more commonly shifted to an inefficient operational aspect of delivering and storing much more proppant than is actually required.
Additionally, to ensure that there is a surplus of proppant, operators rely on manual record keeping and visual inspection of proppant levels within a silo. Such visual inspections also mean that an operator is being more regularly exposed to a dust and particulate that is swirling about or being kicked up during this period of loading or consumption.
Manual tracking and monitoring of the loading and consumption process also presents other challenges such as avoiding proppant contamination, when one proppant is loaded into the wrong silo, or even the possibility of overloading a silo. Ultimately, operators are currently left with proppant management systems that may be generally inaccurate and may result in an inefficient overabundance of proppant on site due to a lack of practical automation for such large scale system.